Sharpe, from Comox, B.C., scored 81.0 points to finish between a pair of Swiss athletes: gold medallist Virginie Faivre (83.8) and Mirjam Jaeger (79.8), who got the bronze.
With three days of competition left, Canada has won eight medals. That's at least twice the total of any other country except the Unites States, which has 10.
Smaine takes men's gold
American Kyle Smaine won the men's event with a score of 88.0, beating Frenchman Joffrey Pollet-Villard (86.6) and Swiss Yannic Lerjen (82.4).
Matt Margetts was the top Canadian. He finished ninth.
The freestyle worlds continue Friday with the snowboard parallel giant slalom finals (CBCSports.ca, 7:30 a.m. ET).